Surgery for patients with endometrioid-type endometrial cancer: is lymphadenectomy above the inferior mesenteric artery necessary?

Objective: The primary objective of this study was to identify the risk of metastasis to lymph nodes above the inferior mesenteric artery (IMA) in endometrioid-type endometrial cancer (EC) and the factors that influence metastasis.

Methods: The study included patients who had been operated on for endometrioid-type EC in three gynecological oncology centers between 2007 and 2023. The supramesenteric lymph node (SM-LN) is the region between the left renal vein and the IMA, whereas the inframesenteric lymph node (IM-LN) is the region between the IMA and the aortic bifurcation, as determined by the level of the IMA.

Results: The study sample comprised 412 patients. The median number of lymph nodes excised per patient was 58. The median count was 37 for pelvic lymph nodes, 21 for para-aortic lymph nodes, 8 for IM-LN, and 13 for SM-LN. In the univariate analysis, the factors that were found to be statistically significant in determining SM-LN metastasis included tumor size, depth of myometrial invasion, uterine serosal invasion, lymphovascular space invasion (LVSI), cervical invasion, peritoneal cytology, adnexal metastasis, omental metastasis, non-nodal extrauterine metastasis, pelvic lymph node metastasis, and IM-LN metastasis. In the multivariate analysis, SM-LN metastasis was independently associated with tumor size, LVSI, pelvic lymph node metastasis, and IM-LN metastasis.

Conclusion: In conclusion, in cases of intermediate-high risk EC, it is important to know that the disease spreads to SM-LN in 7.3% of patients. The efficacy of postoperative adjuvant treatment may be inadequate due to a lack of information regarding the SM-LN region.